Purdue Developes 'Tornado' Lab-on-a-Chip with Nanotweezers

Purdue University researchers have developed a new class of optical nanotweezers that can rapidly trap and detect biomolecules, viruses, and DNA. The technology can also use light to detect cancer or improve the production of medications.

This image shows plasmonic nanotweezers for the lab-on-a-chip technology and the experimental setup used for excitation of the plasmonic nanostructure and imaging of the motion of suspended tracer particles. Courtesy of Purdue University.

The researchers developed a nanostructured plasmonic metafilm by perforating nanoscale holes in a gold film. The metafilm acts as tweezers to capture and trap tiny particles by focusing light onto specific spots on the film and by heating up those spots and creating local thermal gradients in the ambient liquid. This produces a small tornado-like effect.

“All of this is resulting in a revolutionary compact lab-on-a-chip – an innovative approach to detecting and diagnosing a tumor or a viral disease,” said Alexander Kildishev, researcher and associate professor with Purdue’s School of Electrical and Computer Engineering.

The Purdue plasmonic metafilms use a combination of thermal and electric fields to create hydrodynamic flows that result in the rapid transport of suspended particles, bringing them to the surface of the metal film for easy trapping and detection.

The system can sort these tiny particles and then collectively detect sorted patterns such as drug contaminants or water impurities, resulting in potential applications for pharmaceuticals, biohazard detection, and water quality tests.

The Purdue nanotweezers could be also used with inexpensive broadband light sources for combining noble metal and dielectric nanoparticles, which could have applications for long-lasting, nonfading color printing.

The Purdue Office of Technology Commercialization helped secure a patent for the technology. It is available for licensing.